A=\(\frac{\sqrt{a}\left(a\sqrt{a}+1\right)}{a-\sqrt{a}+1}\) \(-\frac{\sqrt{a}\left(2\sqrt{a}+1\right)}{\sqrt{a}}+1\) (dk \(a\ge0\)
=\(\frac{\sqrt{a}\left(\sqrt{a}^3+1\right)}{a-\sqrt{a}+1}-\frac{\sqrt{a}\left(2\sqrt{a}+1\right)}{\sqrt{a}}+1\)
=\(\frac{\sqrt{a}\left(\sqrt{a}+1\right)\left(a-\sqrt{a}+1\right)}{a-\sqrt{a}+1}-\left(2\sqrt{a}+1\right)+1\)
=\(\sqrt{a}\left(\sqrt{a}+1\right)-2\sqrt{a}=a-\sqrt{a}\)